#include <iostream>

using namespace std;

void stringReverse (const char *str, int start)
{
   if (str[start] == '\0') return;
   stringReverse (str + start + 1, 0);
   cout << str[start];
}

int main() {
    const char *test = "Hello World!";
    stringReverse (test, 1);
    return 0;
}
